Heat pipe heat dissipation structure

ABSTRACT

A heat pipe heat dissipation structure includes a main body and at least one first capillary structure. The main body has a first inner side, a second inner side, a third inner side, a fourth inner side and at least one chamber filled with a working fluid. The first capillary structure is disposed in the chamber. The first capillary structure includes a first section disposed on the first inner side and a second section extending from two sides of the first section along the adjacent third and fourth inner sides. The first section has a thickness larger than that of the second section. The heat pipe heat dissipation structure has better heat transfer efficiency.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a heat pipe heat dissipationstructure, and more particularly to a heat pipe heat dissipationstructure, which has better heat transfer efficiency and betteranti-gravity ability and is able to reduce interface thermal resistance.

2. Description of the Related Art

There is a more and more obvious trend to miniaturization of all kindsof high-performance computers, intelligent electronic devices and otherelectrical equipments. To catch up this trend, the heat transfercomponents and heat dissipation components used in these devices havealso been more and more miniaturized and thinned to meet therequirements of users.

It is known that heat pipe is a heat transfer component with excellentthermal conductivity. The thermal conductivity of the heat pipe isseveral times to several tens times the thermal conductivity of copper,aluminum or the like. Therefore, the heat pipe is used as a coolingcomponent and applied to various electronic devices.

As to the configuration, the conventional heat pipes can be classifiedinto heat pipes in the form of circular tubes, heat pipes with D-shapedcross sections and flat-plate heat pipes. The heat pipes are mainly usedto conduct the heat generated by the heat sources in the electronicdevices and cool the heat sources. Currently, in view of easyinstallation and larger contact area, flat-plate heat pipes are widelyused for cooling the heat sources. Following the miniaturization of thecooling mechanism, various flat-plate heat pipes are widely applied tothe electronic devices for conducting the heat generated by theheat-generating components.

The conventional heat pipe structure can be manufactured by means ofmany kinds of methods. For example, the heat pipe can be manufactured insuch a manner that metal powder is filled into a hollow tubular body andsintered to form a capillary structure layer on the inner wall face ofthe tubular body. Then the tubular body is vacuumed and filled with aworking fluid and then sealed. Alternatively, a metal-made mesh body isplaced into the tubular body. The mesh capillary structure body willnaturally outward stretch and expand to attach to the inner wall face ofthe tubular body to form a capillary structure layer. Then the tubularbody is vacuumed and filled with a working fluid and then sealed. Tomeet the requirements for miniaturization and thinning of the electronicdevices, the heat pipe needs to be manufactured with the form of a flatplate.

The flat-plate heat pipe can achieve object of thinning. However, thisleads to another problem. That is, in the flat-plate heat pipe, themetal powder is sintered to form a capillary structure layer fullycoated on the inner wall face of the heat pipe. When compressing theflat-plate heat pipe, the capillary structure, (that is, the sinteredmetal powder or mesh capillary structure body) in the flat-plate heatpipe on two sides of the compressed faces is likely to be squeezed anddamaged. In this case, the capillary structure tends to peel off fromthe inner wall face of the flat-plate heat pipe. This will greatlydeteriorate the heat transfer performance of the thin heat pipe or evenmake the thin heat pipe lose its function. Moreover, although theflat-plate heat pipe can conduct the heat, after thinned and flattened,the internal capillary structure of the flat-plate heat pipe will haveinsufficient capillary attraction. As a result, the working fluid willblock the vapor passage. Furthermore, after thinned, the area of theflow passage inside the flat-plate heat pipe is reduced so that thecapillary attraction is lowered. As a result, the maximum heat transferamount is lowered. On one hand, this is mainly because after thinned,the internal capacity of the flat-plate heat pipe is reduced and on theother hand, this is because after flattened, the central section of theflat-plate heat pipe is recessed to narrow or even block the vaporpassage.

To solve the above problems existing in the conventional heat pipe, somemanufacturers in this field insert a core bar into the internal chamberof the flat-plate heat pipe. The core bar is formed with a specificaxial cut. Metal powder is filled into the space defined by the cut andthe inner wall face of the chamber. Then the metal powder is sintered toform a capillary structure at the central section of the chamber. Thenthe core bar is extracted out. Then the central section of the chamberis compressed and flattened. The capillary structure thermally contactsthe plane parts of the inner wall face of the chamber. In addition,voids are formed on two sides of the capillary structure in the chamberto serve as the vapor passages. Accordingly, better vapor passageimpedance is achievable. However, the cross-sectional area of thecapillary structure is quite narrow so that the capillary attraction islowered. As a result, the anti-gravity thermal efficiency and heattransfer efficiency are poor.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide a heat pipe heatdissipation structure, which has better heat transfer efficiency.

A further object of the present invention is to provide the above heatpipe heat dissipation structure, which has better anti-gravity abilityand is able to reduce interface thermal resistance.

A still further object of the present invention is to provide the aboveheat pipe heat dissipation structure, which is able to bear greaterthermal power impact per unit area.

To achieve the above and other objects, the heat pipe heat dissipationstructure of the present invention includes a main body and at least onefirst capillary structure. The main body has a first inner side, asecond inner side opposite to the first inner side, a third inner side,a fourth inner side opposite to the third inner side and at least onechamber. A working fluid is filled in the chamber. The first capillarystructure is disposed in the chamber. The first capillary structureincludes a first section and a second section. The first section isformed on the first inner side. The second section extends from twosides of the first section along the adjacent third and fourth innersides. The first section has a thickness larger than that of the secondsection. The first and second sections are respectively formed on thefirst, third and fourth inner sides of the main body. Accordingly, thevapor working fluid can fully freely flow within the chamber toadvantageously achieve an excellent heat transfer efficiency, havebetter anti-gravity ability and reduce the pressure impedance. Moreover,the heat pipe heat dissipation structure is able to bear greater thermalpower impact per unit area.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and the technical means adopted by the present inventionto achieve the above and other objects can be best understood byreferring to the following detailed description of the preferredembodiments and the accompanying drawings, wherein:

FIG. 1 is a perspective view of a first embodiment of the heat pipe heatdissipation structure of the present invention;

FIG. 2 is a sectional view of the first embodiment of the heat pipe heatdissipation structure of the present invention;

FIG. 3A is a perspective view of a second embodiment of the heat pipeheat dissipation structure of the present invention, showing anapplication thereof;

FIG. 3B is a sectional view of the second embodiment of the heat pipeheat dissipation structure of the present invention, showing theapplication thereof;

FIG. 3C is a perspective view of the second embodiment of the heat pipeheat dissipation structure of the present invention, showing anotherapplication thereof;

FIG. 3D is a sectional view of the second embodiment of the heat pipeheat dissipation structure of the present invention, showing the otherapplication thereof;

FIG. 4 is a sectional view of a third embodiment of the heat pipe heatdissipation structure of the present invention;

FIG. 5 is a sectional view of the third embodiment of the heat pipe heatdissipation structure of the present invention, showing the applicationthereof;

FIG. 6 is a sectional view of a fourth embodiment of the heat pipe heatdissipation structure of the present invention; and

FIG. 7 is a sectional view of a fifth embodiment of the heat pipe heatdissipation structure of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 1 and 2. FIG. 1 is a perspective view of a firstembodiment of the heat pipe heat dissipation structure of the presentinvention. FIG. 2 is a sectional view of the first embodiment of theheat pipe heat dissipation structure of the present invention. Accordingto the first embodiment, the heat pipe heat dissipation structure of thepresent invention includes a main body 1 and at least one firstcapillary structure 16. The main body 1 has a first inner side 11, asecond inner side 12, a third inner side 13, a fourth inner side 14 andat least one chamber 15. The first inner side 11 is opposite to thesecond inner side 12, while the third inner side 13 is opposite to thefourth inner side 14. The first, second, third and fourth inner sides11, 12, 13, 14 together define the chamber 15. A working fluid is filledin the chamber 15. The working fluid is selected from a group consistingof pure water, inorganic compound, alcohol, ketone, liquid metal,coolant and organic compound. The inner wall face of the chamber 15,(that is, the first, second, third and fourth inner sides 11, 12, 13,14) is a smooth wall face.

The first capillary structure 16 is selected from a grouping consistingof a mesh body, a fiber body, a sintered powder body, a combination ofmesh body and sintered powder body and a microstructure body. In thisembodiment, the first capillary structure 16 is, but not limited to, asintered powder body for illustration purposes only. The first capillarystructure 16 is disposed in the chamber 15 and includes a first section161 and a second section 162. The first section 161 is formed on thefirst inner side 11. The second section 162 extends from two sides ofthe first section 161 along the adjacent third and fourth inner sides13, 14. The first section 161 has a thickness larger than that of thesecond section 162. That is, the first section 161 has a radialextension volume larger than that of the second section 162.

As aforesaid, the thickness of the first section 161 on the first innerside 11 is larger than the thickness of the second section 162 on thethird and fourth inner sides 13, 14. Accordingly, an outer face of thefirst inner side 11 is able to absorb heat generated by aheat-generating component with larger power. In other words, the unitarea of the first capillary structure 16 is larger so that the firstcapillary structure 16 is able to bear greater thermal power impact andtransfer more amount of heat. The second inner side 12 is free from anycapillary structure so as to reduce pressure impedance against flowingof the vapor working fluid 2 in the chamber 15 toward the second innerside 12 (as shown in FIG. 3B). Accordingly, the vapor-liquid circulationefficiency is greatly increased.

According to the above arrangement, the first and second sections 161,162 of the first capillary structure 16 are respectively disposed on thefirst, third and fourth inner sides 11, 13, 14 in the chamber 15 andintegrally connected with each other so as to increase heat transferefficiency and reduce pressure impedance. Therefore, the vapor-liquidcirculation efficiency is effectively enhanced.

Please now refer to FIGS. 3A and 3B and supplementally refer to FIG. 2.FIG. 3A is a perspective view of a second embodiment of the heat pipeheat dissipation structure of the present invention, showing anapplication thereof. FIG. 3B is a sectional view of the secondembodiment of the heat pipe heat dissipation structure of the presentinvention, showing the application thereof. In the second embodiment,the heat pipe heat dissipation structure of the first embodiment iscorrespondingly attached to at least one heat-generating component 4(such as central processor, graphic chip, south bridge and north bridgechips or other processing chip). That is, the outer face of the firstinner side 11 of the main body 1 is attached to at least oneheat-generating component 4 for conducting heat. The liquid workingfluid 3 in the first and second sections 161, 162 of the first capillarystructure 16 on the first, third and fourth inner sides 11, 13, 14 serveto rapidly absorb the heat to evaporate into vapor working fluid 2. Thesecond inner side 12 is free from any capillary structure so that thevapor working fluid 2 can rapidly flow to the second inner side 12.After the vapor working fluid 2 is cooled and condensed into the liquidworking fluid 3 on the second inner side 12, the liquid working fluid 3will flow back to the first section 161 on the first inner side 11 andthe second section 162 on the third and fourth inner sides 13, 14 undergravity to continue the vapor-liquid circulation. Accordingly, anexcellent heat dissipation effect can be achieved.

Please now refer to FIGS. 3C and 3D. FIG. 3C is a perspective view ofthe second embodiment of the heat pipe heat dissipation structure of thepresent invention, showing another application thereof. FIG. 3D is asectional view of the second embodiment of the heat pipe heatdissipation structure of the present invention, showing the otherapplication thereof. At least one heat dissipation unit 5 iscorrespondingly connected with an outer face of the second inner side 12of the main body 1. The heat dissipation unit 5 is selected from a groupconsisting of a heat sink, a radiating fin assembly and a water-cooledunit. The heat dissipation unit 5 serves to speed cooling of the vaporworking fluid 2 flowing to the second inner side 12, whereby the vaporworking fluid 2 can be more rapidly condensed into the liquid workingfluid 3. Accordingly, the vapor-liquid circulation effect of the workingfluid can be enhanced to achieve an excellent heat dissipation effect.

Please now refer to FIG. 4 and supplementally refer to FIG. 1. FIG. 4 isa sectional view of a third embodiment of the heat pipe heat dissipationstructure of the present invention. The third embodiment issubstantially identical to the first embodiment in structure, connectionrelationship and effect and thus will not be repeatedly describedhereinafter. The third embodiment is different from the first embodimentin that the second inner side 12 of the main body 1 is divided into acapillary forming section 121 and at least one capillary-free section122, which is free from any capillary structure. The capillary-freesection 122 is positioned on two sides of the capillary forming section121 in adjacency to the corresponding third and fourth inner sides 13,14 respectively.

At least one swelling capillary section 17 is further disposed in themain body 1. The swelling capillary section 17 is selected from agrouping consisting of a mesh body, a fiber body, a sintered powderbody, a combination of mesh body and sintered powder body and amicrostructure body. The swelling capillary section 17 is disposed onthe capillary forming section 121 of the second inner side 12 oppositeto the first section 161.

The swelling capillary section 17 has a free end 171 extending from thecapillary forming section 121 to connect with the opposite first section161 of the first capillary structure 16. In this embodiment, theswelling capillary section 17 has, but not limited to, the form of ahill. In practice, alternatively, the swelling capillary section 17 canhave a trapezoidal form, rectangular form or conic form.

The first capillary structure 16, the swelling capillary section 17 andthe inner wall of the chamber 15 together define a first vapor passage151 and a second vapor passage 152. The first vapor passage 151 isdefined by the first, second and third inner sides 11, 12, 13, the firstcapillary structure 16 and the swelling capillary section 17. The secondvapor passage 152 is defined by the first, second and fourth inner sides11, 12, 14, the first capillary structure 16 and the swelling capillarysection 17.

Please further refer to FIGS. 4 and 5. The outer face of the first innerside 11 of the main body 1 is attached to at least one heat-generatingcomponent 4 for conducting heat. When the heat-generating component 4generates heat, the liquid working fluid 3 in the first and secondsections 161, 162 on the first, third and fourth inner sides 11, 13, 14rapidly absorb the heat to evaporate into vapor working fluid 2. Asaforesaid, the capillary-free section 122 of the second inner side 12corresponding to the first and second vapor passages 151, 152 is freefrom any capillary structure. Therefore, the vapor working fluid 2 canrapidly flow toward the capillary-free section 122 through the first andsecond vapor passages 151, 152. After the vapor working fluid 2 iscooled and condensed into the liquid working fluid 3 on thecapillary-free section 122 of the second inner side 12, the liquidworking fluid 3 flows back to the first section 161 on the first innerside 11 and the second section 162 on the third and fourth inner sides13, 14 through the first and second vapor passages 151, 152 due togravity or the capillary attraction of the swelling capillary section 17to continue the vapor-liquid circulation. Accordingly, the heat transferefficiency is increased and the pressure impedance is reduced to achievean excellent heat dissipation effect.

Please now refer to FIG. 6, which is a sectional view of a fourthembodiment of the heat pipe heat dissipation structure of the presentinvention. The fourth embodiment is substantially identical to the thirdembodiment in structure, connection relationship and effect and thuswill not be repeatedly described hereinafter. The fourth embodiment isdifferent from the third embodiment in that the swelling capillarysection 17 swells from the first section 161 of the first capillarystructure 16. That is, the swelling capillary section 17 is disposed onthe first section 161 opposite to the second inner side 12. In otherwords, the free end 171 of the swelling capillary section 17 extendsfrom the first section 161 to connect with the opposite capillaryforming section 121.

Please now refer to FIG. 7, which is a sectional view of a fifthembodiment of the heat pipe heat dissipation structure of the presentinvention. The fifth embodiment is substantially identical to the firstembodiment in structure, connection relationship and effect and thuswill not be repeatedly described hereinafter. The fifth embodiment isdifferent from the first embodiment in that a second capillary structure18 is further disposed on the inner wall face of the chamber 15. Thesecond capillary structure 18 is formed on the first, second, third andfourth inner sides 11, 12, 13, 14 of the main body 1 and correspondinglyconnected with the first capillary structure 16. In practice, the secondcapillary structure 18 is selected from a group consisting of a meshbody, a fiber body, a sintered powder body, a combination of mesh bodyand sintered powder body and a structure formed with multiplemicro-channels. In this embodiment, the second capillary structure 18is, but not limited to, a structure formed with multiple micro-channelsfor illustration purposes only. In comparison with the conventional heatpipe, the present invention has the following advantages:

-   -   1. The maximum heat transfer efficiency is increased.    -   2. The present invention has better anti-gravity ability.    -   3. The present invention has smaller interface thermal        resistance.    -   4. The unit area of the first capillary structure is larger so        that the present invention can bear greater thermal power impact        and transfer more amount of heat.

The above embodiments are only used to illustrate the present invention,not intended to limit the scope thereof. It is understood that manychanges and modifications of the above embodiments can be made withoutdeparting from the spirit of the present invention. The scope of thepresent invention is limited only by the appended claims.

What is claimed is:
 1. A heat pipe heat dissipation structurecomprising: a main body having a first inner side, a second inner sideopposite to the first inner side, a third inner side, a fourth innerside opposite to the third inner side and a chamber, a working fluidbeing filled in the chamber; and at least one first capillary structuredisposed in the chamber, the first capillary structure including a firstsection and a second section, the first section being formed on thefirst inner side, the second section extending from two sides of thefirst section along the adjacent third and fourth inner sides, the firstsection having a thickness larger than that of the second section. 2.The heat pipe heat dissipation structure as claimed in claim 1, whereinthe first, second, third and fourth inner sides together define thechamber.
 3. The heat pipe heat dissipation structure as claimed in claim1, wherein the second inner side is divided into a capillary formingsection and at least one capillary-free section, the capillary-freesection being positioned on two sides of the capillary forming sectionin adjacency to the corresponding third and fourth inner sidesrespectively.
 4. The heat pipe heat dissipation structure as claimed inclaim 3, wherein at least one swelling capillary section is furtherdisposed in the main body, the swelling capillary section being disposedon the capillary forming section of the second inner side opposite tothe first section.
 5. The heat pipe heat dissipation structure asclaimed in claim 4, wherein the swelling capillary section has a freeend extending from the capillary forming section to connect with theopposite first section.
 6. The heat pipe heat dissipation structure asclaimed in claim 5, wherein the inner wall of the chamber, the firstcapillary structure and the swelling capillary section together define afirst vapor passage and a second vapor passage, the first vapor passagebeing defined by the first, second and third inner sides, the firstcapillary structure and the swelling capillary section, the second vaporpassage being defined by the first, second and fourth inner sides, thefirst capillary structure and the swelling capillary section.
 7. Theheat pipe heat dissipation structure as claimed in claim 3, wherein atleast one swelling capillary section is further disposed in the mainbody, the swelling capillary section being disposed on the first sectionopposite to the second inner side.
 8. The heat pipe heat dissipationstructure as claimed in claim 7, wherein the swelling capillary sectionhas a free end extending from the first section to connect with theopposite capillary forming section.
 9. The heat pipe heat dissipationstructure as claimed in claim 8, wherein the inner wall of the chamber,the first capillary structure and the swelling capillary sectiontogether define a first vapor passage and a second vapor passage, thefirst vapor passage being defined by the first, second and third innersides, the first capillary structure and the swelling capillary section,the second vapor passage being defined by the first, second and fourthinner sides, the first capillary structure and the swelling capillarysection.
 10. The heat pipe heat dissipation structure as claimed inclaim 1, wherein an outer face of the first inner side of the main bodyis correspondingly attached to at least one heat-generating componentfor conducting heat, at least one heat dissipation unit beingcorrespondingly connected with an outer face of the second inner side ofthe main body, the heat dissipation unit being selected from a groupconsisting of a heat sink, a radiating fin assembly and a water-cooledunit.
 11. The heat pipe heat dissipation structure as claimed in claim1, wherein the inner wall face of the chamber is a smooth wall face. 12.The heat pipe heat dissipation structure as claimed in claim 1, whereina second capillary structure is further disposed on the inner wall faceof the chamber, the second capillary structure being formed on thefirst, second, third and fourth inner sides and correspondinglyconnected with the first capillary structure.
 13. The heat pipe heatdissipation structure as claimed in claim 1, wherein the first capillarystructure is selected from a grouping consisting of a mesh body, a fiberbody, a sintered powder body, a combination of mesh body and sinteredpowder body and a microstructure body.
 14. The heat pipe heatdissipation structure as claimed in claim 4, wherein the swellingcapillary section is selected from a grouping consisting of a mesh body,a fiber body, a sintered powder body, a combination of mesh body andsintered powder body and a microstructure body.
 15. The heat pipe heatdissipation structure as claimed in claim 7, wherein the swellingcapillary section is selected from a grouping consisting of a mesh body,a fiber body, a sintered powder body, a combination of mesh body andsintered powder body and a microstructure body.
 16. The heat pipe heatdissipation structure as claimed in claim 12, wherein the secondcapillary structure is selected from a grouping consisting of a meshbody, a fiber body, a sintered powder body, a combination of mesh 17.The heat pipe heat dissipation structure as claimed in claim 1, whereinthe first section has a radial extension volume larger than that of thesecond section.